Former Gov. Charlie Crist will cast his ballot Thursday, Oct. 22, inviting supporters to join him for a short walk through downtown St. Petersburg as he campaigns for mayor against incumbent Ken Welch. The group will gather at Mary Margaret’s Olde Irish Tavern at 5:30 p.m., walk to the Pinellas County Supervisor of Elections office at 501 First Ave. N., and return to the tavern afterward.